I don’t get high aerobic

Read more here: https://www.firstbeatanalytics.com/en/features/workout-labels/

To get high aerobic you need to do rides that get the labels: Tempo, Threshold or VO2 max

I do all sort of rides but still don’t get it 

this is my ride today

The reading I have there was when I didn’t use a power meter a few days ago and it just stayed

You need to check the workout labels. You see them in each activity or in Training status->load->exercise load.

You might have too long rides. I think shorter rides for about 1 hour or at least shorter than 2 hours might do it.

I had the same , but since i started using a power meter (2 weeks ago) i've been getting readings .

I'd be interested to know what Firstbeat is more interested in when determining the workout label. Heart rate zones, or power zones. They aren't always the same.